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  #1  
Old 08-27-2005, 07:03 PM
Wingnut Wingnut is offline
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Default 87GN misses at idle

Hi, my 87GN misses at idle, its like it has a slight popping out the tail pipe, just wondering if this could be a cam lobe worn ???
Has anyone else had a problem with their GN cams wearing to fast?
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Old 08-28-2005, 03:18 AM
Bill Thompson Bill Thompson is offline
 
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Default Re: 87GN misses at idle

had a miss on an 86 hot air motor + it was a faulty idle air motor.
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Old 08-28-2005, 04:14 PM
Wingnut Wingnut is offline
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Default Re: 87GN misses at idle

Thanks for the reply Bill, my IAC is brand new and reset.
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Old 08-29-2005, 12:24 PM
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kenmosher kenmosher is offline
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Default Re: 87GN misses at idle

A slight miss is the toughest to track down ... here's some thoughts:
  • IAC reset
  • Dirty failing crank sensor
  • Dirty/leaking fuel injector
  • Air leak past the MAF (any scan tool readings?)
  • PCV valve not sealing correctly (plug the hose to the plenum just to see if it changes)
  • EGR not seating/dirty and leaking
  • Rounded cam lobe (have to check valve lift on suspected cylinders)
  • Ignition module flaky
  • Idle cal in chip too lean
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  #5  
Old 09-06-2005, 06:38 PM
Wingnut Wingnut is offline
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Default Re: 87GN misses at idle

Hi Ken yes it is a tough one, most of those things you listed I have gone thru. I am starting to think it is a rounded cam lobe or injector.Crank sensor Pvc ignition mod and IAC new,and IAC reset - works great egr is working fine, I dont have a scan tool yet working on that one. And if anything it is running rich (cannot pass emissions) (Brand new build with 1000 Kms on it).There are no vacuum leaks. Thanks for the reply !
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Old 09-06-2005, 10:22 PM
85T/TYPE/HYPE 85T/TYPE/HYPE is offline
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Default Re: 87GN misses at idle

Im No Expert But If Its A Recent Rebuild With 1000 Kms I Would Think That The Cam Would Be Good (and Everything Else Replaced)and Look At The Injectors First. Kenmosher Was Right On The Button With Mine (crank Sensor) It Had A Light Miss To It (only At Idle) Then It Just Went Up And Died On Me!! And I Was Clueless!! Still Am!!
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Old 09-07-2005, 12:43 PM
Wingnut Wingnut is offline
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Default Re: 87GN misses at idle

The cam is an old one but only 3 years old, so still a possibility. Crank sensor is 2 years old but could still be the problem Thanks for the reply. Its weird how it is only at idle, it runs great on the highway.
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  #8  
Old 09-07-2005, 03:52 PM
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Keller Keller is offline
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Lightbulb Re: 87GN misses at idle

Could be a lifter not staying pumped up at lower pressures. Even if the cam is good.
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